The “Med” line on your paycheck is one of two things: the mandatory federal Medicare tax, or your share of an employer-sponsored health insurance premium. They have nothing to do with each other beyond the shared abbreviation. The med deduction on your paycheck is the Medicare tax when it equals 1.45% of your gross wages and shifts with your hours or pay; it’s a health insurance premium when it’s a flat dollar amount that stays the same every pay period.
How to Tell Which “Med” You’re Looking At
Payroll systems label these inconsistently. Some stubs spell out “Medicare Tax” or “FICA-Med” for the tax and “Medical Ins” or “MEDINS” for the insurance premium. Others just print “Med” for both and leave you to work it out.
Do the math. Take your gross pay for the period and multiply it by 0.0145. If the “Med” amount matches that result or sits very close to it, you’re looking at the Medicare tax. If the number doesn’t budge from paycheck to paycheck regardless of overtime or a bonus, it’s almost certainly your health insurance premium. Most stubs also group deductions into categories like “Taxes” and “Benefits” or “Pre-Tax Deductions,” which is another giveaway.
If you’re enrolled in employer health coverage, you should see both deductions on every stub. One “Med” line on its own usually means either your payroll system collapses FICA into a single row, or you never elected health insurance through your employer.
The Mandatory Medicare Tax
Every paycheck you earn as a W-2 employee has 1.45% taken out for Medicare, the federal health insurance program that covers people 65 and older and certain younger individuals with disabilities. Your employer pays a matching 1.45%, so 2.9% of your wages goes to Medicare in total.1Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates You never see the employer’s half on your stub.
The tax is part of FICA (the Federal Insurance Contributions Act), which also includes Social Security tax at 6.2%. Together, FICA withholding comes to 7.65% of your gross wages. One key difference between the two: Social Security tax stops once your earnings hit $184,500 in 2026, but Medicare tax has no cap.2Internal Revenue Service. Publication 15 (2026), Employer’s Tax Guide Every dollar you earn, no matter how high your income climbs, carries the 1.45% Medicare deduction.
Your employer handles all of this automatically, withholding your share and sending it to the U.S. Treasury along with the matching portion. You can’t opt out, negotiate it down, or defer it.
The Additional 0.9% for High Earners
Once your wages from a single employer pass $200,000 in a calendar year, an extra 0.9% Medicare tax kicks in on every dollar above that line. Your employer must start withholding it at that point regardless of your filing status.3Internal Revenue Service. Questions and Answers for the Additional Medicare Tax That brings your employee-side Medicare rate to 2.35% on wages above the threshold. Your employer does not match this surcharge.
The $200,000 withholding trigger is a blunt instrument. Your actual liability depends on how you file:
- Single or head of household: 0.9% on wages above $200,000
- Married filing jointly: 0.9% on combined wages above $250,000
- Married filing separately: 0.9% on wages above $125,000
That mismatch creates problems in both directions. A married couple filing jointly who each earn $150,000 won’t have anything extra withheld by either employer, but they owe the surcharge on $50,000 of combined income. A single filer with one job paying $210,000 will have the surcharge withheld correctly with nothing to adjust at tax time.3Internal Revenue Service. Questions and Answers for the Additional Medicare Tax
If you expect to owe the Additional Medicare Tax but your employer won’t withhold enough, the IRS says you should either make quarterly estimated tax payments or submit a new Form W-4 requesting additional income tax withholding to cover the gap.3Internal Revenue Service. Questions and Answers for the Additional Medicare Tax Ignore it and you can face an underpayment penalty when you file.
You settle up on the surcharge with Form 8959 when you file your annual return. The form is required if the Medicare wages on any single W-2 exceed $200,000, or if your total Medicare wages (plus any self-employment income) exceed your filing status threshold.4IRS. Instructions for Form 8959, Additional Medicare Tax If your employer over-withheld, say you’re married filing jointly and a $210,000 salary triggered withholding but your household income stays under $250,000, the excess is credited against your total tax bill and can come back as a refund.
The Health Insurance Premium Deduction
The other “Med” on your stub is your share of employer-sponsored health insurance. This one is voluntary. It only shows up if you enrolled in coverage during open enrollment or after a qualifying life event, and the amount is fixed for the plan year unless you change your coverage.
How much depends on the plan you picked and how much your employer subsidizes. The average employee contribution in 2025 was about $120 per month for single coverage and $571 per month for family coverage.5KFF. 2025 Employer Health Benefits Survey Your number can be higher or lower depending on the plan tier you selected and whether you chose an HMO, PPO, or high-deductible plan.
The per-paycheck deduction depends on your pay frequency, not your monthly premium. Paid semi-monthly (24 paychecks a year)? Divide your annual premium by 24. Paid biweekly (26 paychecks a year)? Divide by 26. The biweekly figure will be slightly smaller per check even though the annual total is the same. Your benefits enrollment documents will show what the correct per-stub number should be.
Why Pre-Tax Premiums Are Worth So Much
Most employers run health insurance premiums through a Section 125 cafeteria plan, meaning your premium comes out of your pay before taxes are calculated. The IRS treats qualified benefits under a cafeteria plan as exempt from federal income tax, Social Security tax, and Medicare tax.6Internal Revenue Service. FAQs for Government Entities Regarding Cafeteria Plans That triple exemption is what makes pre-tax premiums valuable.
Here’s how it works. Say you earn $5,000 gross per pay period and your health premium is $300 pre-tax. Your taxable wages for federal income tax drop to $4,700, and that’s the figure that eventually shows up in Box 1 of your W-2. Your Medicare wages (Box 5) also drop to $4,700, and so do your Social Security wages (Box 3).7Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) The Medicare tax itself, by contrast, is calculated on your gross wages and doesn’t reduce your taxable income at all.
Who Is Exempt from Medicare Tax
The Medicare tax applies to nearly every U.S. worker, but a few narrow exceptions exist:
- Nonresident alien students on F-1, J-1, or M-1 visas are exempt from Medicare tax on qualifying employment for their first five calendar years in the United States, as long as the work is authorized by USCIS and connected to the purpose of their visa.
- Students enrolled at least half-time at a college or university who work for that same institution are exempt from FICA, including Medicare tax, as long as the job is incidental to their studies.
These exemptions don’t extend to spouses or dependents on derivative visa statuses, and they end once the student changes to a different immigration status or becomes a resident alien.8Internal Revenue Service. Foreign Student Liability for Social Security and Medicare Taxes Members of certain religious groups who have received IRS approval can also be exempt, though that applies to very few people. If none of these describes you, there is no way to opt out.
What to Do If the Number Looks Wrong
If your Medicare tax withholding doesn’t match 1.45% of your gross pay, the most likely explanation is a rounding quirk in your payroll system, but flag it with your payroll or HR department anyway. An employer that fails to withhold the correct Medicare tax remains liable for the amount it should have withheld until the employee pays it, and the employer can face penalties on top of that.9eCFR. 26 CFR 31.3102-4 Special Rules Regarding Additional Medicare Tax Catching it early saves everyone a headache at year-end.
For health insurance premiums, compare the per-paycheck deduction against your enrollment confirmation. Divide your annual premium by the number of pay periods (24 for semi-monthly, 26 for biweekly, 52 for weekly). If the numbers don’t line up, contact HR. Payroll systems occasionally miscalculate after mid-year coverage changes or when a pay frequency switches. Fixing an error in January is far easier than unwinding twelve months of incorrect deductions.